/*
  ManagedDatasource.cpp

  Qore Programming Language

  Copyright 2003 - 2015 Qore Technologies, sro

  Permission is hereby granted, free of charge, to any person obtaining a
  copy of this software and associated documentation files (the "Software"),
  to deal in the Software without restriction, including without limitation
  the rights to use, copy, modify, merge, publish, distribute, sublicense,
  and/or sell copies of the Software, and to permit persons to whom the
  Software is furnished to do so, subject to the following conditions:

  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  DEALINGS IN THE SOFTWARE.

  Note that the Qore library is released under a choice of three open-source
  licenses: MIT (as above), LGPL 2+, or GPL 2+; see README-LICENSE for more
  information.
*/

#include <qore/Qore.h>
#include <qore/intern/ManagedDatasource.h>

#include <stdlib.h>
#include <string.h>

void ManagedDatasource::cleanup(ExceptionSink *xsink) {
   // this thread has the transaction lock
   AutoLocker al(&ds_lock);
   assert(isInTransaction());

   xsink->raiseException("DATASOURCE-TRANSACTION-EXCEPTION", "%s:%s@%s: TID %d terminated while in a transaction; transaction will be automatically rolled back and the lock released", getDriverName(), getUsernameStr().c_str(), getDBNameStr().c_str(), gettid());
   Datasource::rollback(xsink);
   setTransactionStatus(false);
   releaseLockIntern();
}

void ManagedDatasource::destructor(ExceptionSink *xsink) {
   AutoLocker al(&ds_lock);
   if (tid == gettid() || tid == -1)
      // closeUnlocked will throw an exception if a transaction is in progress (and release the transaction lock if held)
      closeUnlocked(xsink);
   else
      xsink->raiseException("DATASOURCE-ERROR", "%s:%s@%s: TID %d deleted Datasource while TID %d is holding the transaction lock", getDriverName(), getUsernameStr().c_str(), getDBNameStr().c_str(), gettid(), tid);
}

void ManagedDatasource::deref(ExceptionSink *xsink) {
   if (ROdereference()) {
      close(xsink);
      delete this;
   }
}

// this function is only called by remove_thread_resource()
// during a call, meaning that the reference count cannot reach 0,
// meaning that the close method will never be run here
void ManagedDatasource::deref() {
#ifdef DEBUG
   assert(!ROdereference());
#else
   ROdereference();
#endif
}

int ManagedDatasource::grabLockIntern() {
   int ctid = gettid();

   if (tid == ctid)
      return 0;

   while (tid != -1) {
      ++waiting;
      if (tl_timeout_ms) {
	 int rc = cond.wait(&ds_lock, tl_timeout_ms);
	 --waiting;
	 if (!rc)
	    continue;
	 printd(5, "ManagedDatasource::grabLockIntern() this=%p timed out after %dms waiting for tid %d to release lock\n", this, tl_timeout_ms, tid);
	 return -1;
      }
      else
	 cond.wait(&ds_lock);
      --waiting;
   }

   tid = ctid;

   return 0;
}

int ManagedDatasource::grabLock(ExceptionSink *xsink) {
   if (grabLockIntern() < 0) {
      endDBActionIntern();
      const char *un = getUsername();
      const char *db = getDBName();
      xsink->raiseException("TRANSACTION-LOCK-TIMEOUT", "%s:%s@%s: TID %d timed out on datasource '%s@%s' after waiting %d millisecond%s on transaction lock held by TID %d",
			    getDriverName(), getUsernameStr().c_str(), getDBNameStr().c_str(),
			    gettid(), un ? un : "<n/a>", db ? db : "<n/a>", tl_timeout_ms,
			    tl_timeout_ms == 1 ? "" : "s", tid);
      return -1;
   }
   return 0;
}

void ManagedDatasource::releaseLockIntern() {
   assert(tid == gettid());
   tid = -1;
   if (waiting)
      cond.signal();
}

void ManagedDatasource::releaseLock() {
   AutoLocker al(ds_lock);
   releaseLockIntern();
}

void ManagedDatasource::forceReleaseLockIntern() {
   tid = -1;
   if (waiting)
      cond.signal();
}

ManagedDatasource *ManagedDatasource::copy() {
   return new ManagedDatasource(*this);
}

int ManagedDatasource::startDBAction(ExceptionSink *xsink, bool &new_transaction) {
   AutoLocker al(&ds_lock);

   // save previous trans lock status
   new_transaction = (tid != gettid());

   // first grab the transaction lock
   if (grabLock(xsink))
      return -1;

   // open the datasource if necessary
   if (!isOpen() && (Datasource::open(xsink) || *xsink)) {
      // release transaction lock if necessary
      if (new_transaction)
	 releaseLockIntern();
      return -1;
   }

   //printd(0, "ManagedDatasource::startDBAction() this=%p need_lock=%d new_trans=%p had_lock=%d\n", this, need_transaction_lock, new_transaction, had_lock);
   return 0;
}

bool ManagedDatasource::endDBActionIntern(char cmd, bool new_transaction) {
   if (cmd == DAH_ACQUIRE) {
      // save thread resource if we just started a transaction
      if (new_transaction)
	 set_thread_resource(this);
   }
   else if (cmd) {
      assert(cmd == DAH_RELEASE);

      // transaction is complete, remove the transaction thread resource
      if (!new_transaction)
	 remove_thread_resource(this);

      releaseLockIntern();
   }

   return tid == gettid();
}

bool ManagedDatasource::endDBAction(char cmd, bool new_transaction) {
   AutoLocker al(&ds_lock);
   return endDBActionIntern(cmd, new_transaction);
}

void ManagedDatasource::setTransactionLockTimeout(int t_ms) {
   tl_timeout_ms = t_ms;
}

int ManagedDatasource::getTransactionLockTimeout() const {
   return tl_timeout_ms;
}

void ManagedDatasource::setAutoCommit(bool ac, ExceptionSink *xsink) {
   DatasourceLockHelper dslh(*this, xsink);
   if (!dslh)
      return;

   Datasource::setAutoCommit(ac);
}

AbstractQoreNode *ManagedDatasource::select(const QoreString *query_str, const QoreListNode *args, ExceptionSink *xsink) {
   DatasourceActionHelper dbah(*this, xsink);
   if (!dbah)
      return 0;

   return Datasource::select(query_str, args, xsink);
}

QoreHashNode *ManagedDatasource::selectRow(const QoreString *sql, const QoreListNode *args, ExceptionSink *xsink) {
   DatasourceActionHelper dbah(*this, xsink);
   if (!dbah)
      return 0;

   return Datasource::selectRow(sql, args, xsink);
}

AbstractQoreNode *ManagedDatasource::selectRows(const QoreString *query_str, const QoreListNode *args, ExceptionSink *xsink) {
   DatasourceActionHelper dbah(*this, xsink);
   if (!dbah)
      return 0;

   return Datasource::selectRows(query_str, args, xsink);
}

AbstractQoreNode *ManagedDatasource::exec(const QoreString *query_str, const QoreListNode *args, ExceptionSink *xsink) {
   DatasourceActionHelper dbah(*this, xsink, getAutoCommit() ? DAH_NOCHANGE : DAH_ACQUIRE);
   if (!dbah)
      return 0;

   //printd(0, "ManagedDatasource::exec() st=%d tid=%d\n", start_transaction, tid);

   return Datasource::exec(query_str, args, xsink);
}

AbstractQoreNode *ManagedDatasource::execRaw(const QoreString *query_str, ExceptionSink *xsink) {
   DatasourceActionHelper dbah(*this, xsink, getAutoCommit() ? DAH_NOCHANGE : DAH_ACQUIRE);
   if (!dbah)
      return 0;

   return Datasource::execRaw(query_str, xsink);
}

QoreHashNode* ManagedDatasource::describe(const QoreString* sql, const QoreListNode* args, ExceptionSink* xsink) {
   DatasourceActionHelper dbah(*this, xsink);
   if (!dbah)
      return 0;

   return Datasource::describe(sql, args, xsink);
}

bool ManagedDatasource::beginTransaction(ExceptionSink *xsink) {
   DatasourceActionHelper dbah(*this, xsink, getAutoCommit() ? DAH_NOCHANGE : DAH_ACQUIRE);
   if (!dbah)
      return false;

   Datasource::beginTransaction(xsink);
   //printd(0, "ManagedDatasource::beginTransaction() this=%p isInTransaction()=%d\n", this, isInTransaction());

   return dbah.newTransaction();
}

int ManagedDatasource::commit(ExceptionSink *xsink) {
   DatasourceActionHelper dbah(*this, xsink, getAutoCommit() ? DAH_NOCHANGE : DAH_RELEASE);
   if (!dbah)
      return -1;

   return Datasource::commit(xsink);
}

int ManagedDatasource::rollback(ExceptionSink *xsink) {
   DatasourceActionHelper dbah(*this, xsink, getAutoCommit() ? DAH_NOCHANGE : DAH_RELEASE);
   if (!dbah)
      return -1;

   return Datasource::rollback(xsink);
}

int ManagedDatasource::open(ExceptionSink *xsink) {
   DatasourceLockHelper dslh(*this, xsink);
   if (!dslh)
      return -1;

   return Datasource::open(xsink);
}

// returns 0 for OK, -1 for exception
int ManagedDatasource::closeUnlocked(ExceptionSink *xsink) {
   int rc = 0;

   if (grabLock(xsink))
      return -1;

   if (isOpen()) {
      if (isInTransaction()) {
	 if (!wasConnectionAborted()) {
	    // FIXME: check for statement
	    xsink->raiseException("DATASOURCE-TRANSACTION-EXCEPTION", "%s:%s@%s: Datasource closed while in a transaction; transaction will be automatically rolled back and the lock released", getDriverName(), getUsernameStr().c_str(), getDBNameStr().c_str());
	    Datasource::rollback(xsink);
	 }
	 remove_thread_resource(this);
	 setTransactionStatus(false);
	 // force-exit the transaction lock
	 forceReleaseLockIntern();
	 rc = -1;
      }

      Datasource::close();
   }

   return rc;
}

int ManagedDatasource::close(ExceptionSink *xsink) {
   AutoLocker al(&ds_lock);
   return closeUnlocked(xsink);
}

// closes and re-opens to reset a database connection
int ManagedDatasource::reset(ExceptionSink *xsink) {
   AutoLocker al(&ds_lock);
   if (closeUnlocked(xsink))
      return -1;
   // open the connection
   return Datasource::open(xsink);
}

void ManagedDatasource::setPendingUsername(const char *u) {
   AutoLocker al(&ds_lock);
   Datasource::setPendingUsername(u);
}

void ManagedDatasource::setPendingPassword(const char *p) {
   AutoLocker al(&ds_lock);
   Datasource::setPendingPassword(p);
}

void ManagedDatasource::setPendingDBName(const char *d) {
   AutoLocker al(&ds_lock);
   Datasource::setPendingDBName(d);
}

void ManagedDatasource::setPendingDBEncoding(const char *c) {
   AutoLocker al(&ds_lock);
   Datasource::setPendingDBEncoding(c);
}

void ManagedDatasource::setPendingHostName(const char *h) {
   AutoLocker al(&ds_lock);
   Datasource::setPendingHostName(h);
}

void ManagedDatasource::setPendingPort(int port) {
   AutoLocker al(&ds_lock);
   Datasource::setPendingPort(port);
}

QoreStringNode *ManagedDatasource::getPendingUsername() const {
   AutoLocker al(&ds_lock);
   return Datasource::getPendingUsername();
}

QoreStringNode *ManagedDatasource::getPendingPassword() const {
   AutoLocker al(&ds_lock);
   return Datasource::getPendingPassword();
}

QoreStringNode *ManagedDatasource::getPendingDBName() const {
   AutoLocker al(&ds_lock);
   return Datasource::getPendingDBName();
}

QoreStringNode *ManagedDatasource::getPendingDBEncoding() const {
   AutoLocker al(&ds_lock);
   return Datasource::getPendingDBEncoding();
}

QoreStringNode *ManagedDatasource::getPendingHostName() const {
   AutoLocker al(&ds_lock);
   return Datasource::getPendingHostName();
}

int ManagedDatasource::getPendingPort() const {
   AutoLocker al(&ds_lock);
   return Datasource::getPendingPort();
}

AbstractQoreNode *ManagedDatasource::getServerVersion(ExceptionSink *xsink) {
   DatasourceActionHelper dbah(*this, xsink);
   if (!dbah)
      return 0;

   return Datasource::getServerVersion(xsink);
}

AbstractQoreNode *ManagedDatasource::getClientVersion(ExceptionSink *xsink) const {
   return Datasource::getClientVersion(xsink);
}

QoreHashNode* ManagedDatasource::getOptionHash(ExceptionSink* xsink) {
   DatasourceActionHelper dbah(*this, xsink);
   if (!dbah)
      return 0;
   return Datasource::getOptionHash();
}

int ManagedDatasource::setOption(const char* opt, const QoreValue val, ExceptionSink* xsink) {
   DatasourceActionHelper dbah(*this, xsink);
   if (!dbah)
      return 0;
   return Datasource::setOption(opt, val, xsink);
}

AbstractQoreNode* ManagedDatasource::getOption(const char* opt, ExceptionSink* xsink) {
   DatasourceActionHelper dbah(*this, xsink);
   if (!dbah)
      return 0;
   return Datasource::getOption(opt, xsink);
}

void ManagedDatasource::setEventQueue(Queue* q, AbstractQoreNode* arg, ExceptionSink* xsink) {
   AutoLocker al(&ds_lock);
   Datasource::setEventQueue(q, arg, xsink);
}
